4. Dune Preservation and Restoration
Sand dunes are important components of the littoral budget. Dunes trap windblown sand, store excess beach sand, and serve as natural erosion buffers, protecting beach-front property and coastal infrastructure during storms and high-wave events. Pristine dunes are vegetated by native Hawaiian species such as 'aki'aki, 'akulikuli, naupaka, and pohuehue, which are salt-tolerant, have dense root systems, and are effective wind-breaks and wave buffers (Figures 8 to 11). Healthy sand dunes are vital to the health of the beach and nearshore marine environment.
Figure 8. Vegetated dune, Kanaha, Maui. Naupaka shrub and 'aki'aki and pohuehue (with purple flowers) ground cover at center, 'aki'aki (sparse ground cover) in background.
Because of the natural erosion buffer that coastal dunes provide, dunes should be preserved and, in some cases, restored. Dune restoration projects took place at Kama'ole I in 1983, Kama'ole II in 1984, and Memorial Beach Park in 1987 (Figure 12). All three of these restoration projects significantly enhanced the recreational value of the beach and upland areas.
Figure 9. Close up of 'aki'aki. Photo from JOHNSTONE, 1997.
Figure 10. Close up of 'akulikuli. Photo from JOHNSTONE, 1997.
Figure 11. Close up of pohuehue, Honokahua, Maui Common name: beach morning glory.
Figure 12. Dune restoration project at Kama'ole II in 1984.
Objectives
4.1) To preserve existing sand dunes4.2) To restore degraded sand dunes
Recommendations
4.1a) Map coastal dunes, and limit development on top of or in front of these dunes4.1b) Prohibit grading (leveling) or mining of coastal dunes
4.1c) Guide landscaping in dune areas (e.g., limit topsoil fill, encourage the planting of native coastal species rather than turf grass, which is not consistent with the natural littoral environment)
4.1d) Establish moveable dune walkovers to provide pedestrian access without trampling dune vegetation (Figure 13)
4.2a) Encourage and support dune restoration efforts (dune fencing, revegetation, sand nourishment, etc.)
4.2b) Publish a handbook detailing the methodology for future dune restoration projects
Figure 13. Dune walkover at Kama'ole II, Maui.
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